Process for the manufacture of facsimiles on wood



Sept. 3, 1935. KAUFMANN 2,013,511

PROCESS FOR THE MANUFACTURE OF FAGSIMILES ON WOOD Filed Aug. 16, 1934 INVENTOR HANS KAUFMANN 1, Willi m ATTORNEY Patented Sept. 3, 1935 UNITED STATES PATENT OFFICE PROCESS FOR THE MANUFACTURE OF FAOSIMILES ON WOOD Hans Kaufmann, Frankfort-on-the-Main,- Germany Application August 16, 1934, Serial No. 740,120 In Germany August 18, 1933 1 Claim.

The invention concerns the production of facsimiles, for example of knotted wood effects, pictorial representations and the like on wood surfaces, in connection with colour carrying trans- 5 parent sheets of cellulose derivatives, such as,

for example, cellulose hydrate or acetylcellulose known metachromotype process by which trans-. fers are made with the help of a paper covered with a rice-gum-layer. The products obtained in this way possess, in general, the property of forming smooth edges when out, which means they do not exfoliate at the cut edges. The production is apart from certain difficulties due to the representation vehicle, to a certain extent detailed and leads generally, due to the necessary transfer of the representation from its vehicle to the wood surfaces, to the injury of the definition of printing of the representation. It has also previously been proposed in order to obtain brilliant and permanent colour-coatings, to cover the base with sheets, for example; to lay on a groundwork of wood, the desired representations such as photographs, etc., on their reverse side and to fasten them down firmly thereon by means of a covering of pyralin sheet or the like. The fixing down is carried out either by wetting the picture with alcohol or any other liquid in which the sheets chosen are soluble, and thereupon subx mitting the whole to pressure, or by employing only pressure and heat.

For the decoration of woods which are to be used as objects of utility such as the production of pictures, furniture or the like, such processes are not suitable, for failing a perfect combination of the inlaid representation pressed onto the wood-surface, by the covering sheet, slight breaks in the covering layer lead to immediate destruction, whilst the results produced by such a means of decoration are not technically and economically suitable for the advantageous production of facsimiles for the purposes mentioned above. It has also already been proposed to treat suitable bases such as leather, metal or pliable wood sheets with shining covers or also facsimiles in such a way that the base to be operated on is covered with sheets under the influence of heat or pressure, which if necessary, can carry imprinted colours, so that one of the glass-clear (Cl. 41-22) E representations covered by a sheet can be aflixed to the wood base or the like.

This process possesses in contradistinction to the afore-mentioned metachromotype process the advantage of greater simplicity in operation, 5 but shows in contradistinction to the product thus obtained, the serious disadvantage that the facsimiles produced only adhere lightly to the base and especially by the cutting of surfaces thus handled a slight exfoliating of the decora- 1o tive layer and sheet takes place. Endeavours have been made to overcome this disadvantage, by covering the wood surface with lacquer by pressing a further thin transparent sheet onto the wood surface before putting on the colour 15 bearing sheet. But in these cases also a comparatively slight exfoliation was visible, quite apart from the fact that in consequence the useful advantages in comparison with the metachromotype process were lost.

It has now been found according to this invention that facsimiles can be obtained with especially remarkable adhesive properties and without any injury to the printing definition, on wood surfaces. if the wood to be decorated is subjected 25 to a heat treatment at temperatures lying above C. and the sheets provided with the colouring layer, are afiixed immediately after the heating process onto the suitable smoothly polished upper surface while avoiding an absorption of a 30 humidity through the wood pores, and pressed under the application of pressure and heat onto the upper surface.

It has been ascertained that the resistance to scratching, production of smoother cutting edges and security against exfoliation of the facsimiles produced in this way are positively increased as compared with the facsimiles produced according to the known process and thereby the operative process itself in comparison with that of meta- 40 chromotype is substantially simplified, quite apart from the fact that the products produced according to the process of the invention are especially distinguished by the clarity and exactness of the reproduction in contradistinction to those of all 65 known processes.

The accompanying drawing illustrates in a per- 'spective view an example of a transparent sheet and a wooden base assembled through the process as per the invention, a portion of the sheet being 50 lifted for the purpose of showing its underside.

I is the wooden base having a polished surface 2, which is to be decorated. The transparent sheet 3 with the ornamentation 4 on its lower side is pressed onto the surface 2 under the application 55 uum container keptat the requisite temperature,

in a vacuum drying coil as conventionally used in the heat treatment of wood, or the like, so long as care is taken that the benefit obtained from the heating room is not lost by the possibility of an absorption of atmospheric moisture immediately before the pressing of the sheets.

The production of smoothly out surfaces makes possible the use of facsimiles also for the production of the finest tarsia-work pictures or the like, as also the preservation of the definition'of printing in the employment of the process of decorating with the finest patterned representations. Durable picturesque representations are especially made possible in the most varied tone tints.

- The heat treatment according to the invention is not a replacement of the natural drying of the wood in the afore-mentioned process. There can have taken place, for instance, in addition to the employment of the heat treatment according to the invention, one or more pre-dryingtreatments of the wood, for instance to drive'ofl large proportions of moisture picked up in storage. If

desired a preliminary pre-drying can be omitted and the chief drying of the wood carried out at the same time as the heating treatment which immediately precedes the application of the sheets.

For carrying out the heat treatment according to the invention temperatures not much above 80 C., for example up to 90 C., are, in general, sufficient. If desired, however, much higher temperatures may be used which in the first place, for instance, ensure that the moisture content of the work-room does not provide an especially strong tendency for the re-absorption of air moisture.

What I claim is:

A process for the production of facsimiles on wood comprising heating the wood to be treated to a temperature of at least 80 C., immediately thereafter, before the wood is able to absorb moisture from the air, applying to the smooth surface of the wood a colour-containing transparent sheet of a cellulose derivative, and pressing the said sheet on to the wood surface under the application of heat and pressure.

HANS KAUFMANN. 

